- A Water-Soluble Iridium Photocatalyst for Chemical Modification of Dehydroalanines in Peptides and Proteins
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Dehydroalanine (Dha) residues are attractive noncanonical amino acids that occur naturally in ribosomally synthesised and post-translationally modified peptides (RiPPs). Dha residues are attractive targets for selective late-stage modification of these complex biomolecules. In this work, we show the selective photocatalytic modification of dehydroalanine residues in the antimicrobial peptide nisin and in the proteins small ubiquitin-like modifier (SUMO) and superfolder green fluorescent protein (sfGFP). For this purpose, a new water-soluble iridium(III) photoredox catalyst was used. The design and synthesis of this new photocatalyst, [Ir(dF(CF3)ppy)2(dNMe3bpy)]Cl3, is presented. In contrast to commonly used iridium photocatalysts, this complex is highly water soluble and allows peptides and proteins to be modified in water and aqueous solvents under physiologically relevant conditions, with short reaction times and with low reagent and catalyst loadings. This work suggests that photoredox catalysis using this newly designed catalyst is a promising strategy to modify dehydroalanine-containing natural products and thus could have great potential for novel bioconjugation strategies.
- van Lier, Roos C. W.,de Bruijn, A. Dowine,Roelfes, Gerard
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p. 1430 - 1437
(2020/12/11)
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- Design, synthesis and biological evaluation of low molecular weight CXCR4 ligands
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The chemokine receptor CXCR4/stromal cell-derived factor-1 (SDF-1: CXCL12) signaling axis represents a crucial drug target due to its relevance to several diseases such as HIV-1 infection, cancer, leukemia, and rheumatoid arthritis. With the aim of enhancing the binding affinity and anti-HIV activity of a potent CXCR4 ligand as a lead, 23 low molecular weight compounds containing dipicolylamine (Dpa) and cyclam cationic moieties with varying spacers and spatial positioning were designed, synthesized and biologically evaluated. All of the synthesized compounds screened at 1.0 μM in the NanoBRET assay system exhibited >70% inhibition of the binding of a competitive probe TAMRA-Ac-TZ14011 (10 nM) to CXCR4 in the presence of zinc (II) ion. Furthermore, selected compounds 3, 8, 9, 19 and 21 with spatial distances between the next carbon to Dpa and the next carbon to cyclam within the range of 6.5–7.5 ? showed potent binding affinity selective for CXCR4 with IC50 values of 1.6, 7.9, 5.7, 3.5 and 4.5 nM, respectively, with corresponding high anti-HIV activity with EC50s of 28, 13, 21, 28 and 61 nM, respectively, in the presence of zinc (II) ion. Some compounds with remarkably more potent CXCR4-binding affinity than that of an initial lead were obtained. These compounds interact with different but overlapping amino acid residues of CXCR4. The present studies have developed new low molecular weight CXCR4 ligands with high CXCR4-binding and anti-HIV activities, which open avenue into the development of more potent CXCR4 ligands.
- Sakyiamah, Maxwell M.,Kobayakawa, Takuya,Fujino, Masayuki,Konno, Makoto,Narumi, Tetsuo,Tanaka, Tomohiro,Nomura, Wataru,Yamamoto, Naoki,Murakami, Tsutomu,Tamamura, Hirokazu
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supporting information
p. 1130 - 1138
(2019/02/16)
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- Rational Design of Phosphorescent Iridium(III) Complexes for Selective Glutathione Sensing and Amplified Photodynamic Therapy
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It is a huge challenge to avoid irreversible damage to normal tissues during irradiation in photodynamic therapy (PDT) for cancer. An effective strategy is to develop smart photosensitizers, which exhibit amplified generation of reactive oxygen species (ROS) through triggering specific reaction in the tumor microenvironment. In this work, we designed a class of glutathione (GSH)-activatable photosensitizers (Ir1 and Ir4) based on an effective strategy of GSH-induced nucleophilic substitution reaction. The addition of GSH, induced changes in both phosphorescence intensity and lifetime of photosensitizers with high sensitivity. Importantly, the amount of singlet oxygen generated was increased significantly by GSH-induced activation reaction. Hence, the photosensitizers can selectively distinguish cancer cells from normal cells through luminescence and lifetime imaging, and can amplify PDT effects in cancer cells, owing to the evidently higher level of GSH compared to normal cells. This work presents a novel paradigm for GSH-amplified PDT against cancer cells and provides a new avenue for smart-responsive theranostic systems that can avoid nonspecific damage to normal cells.
- Huang, Tianci,Yu, Qi,Liu, Shujuan,Zhang, Kenneth Yin,Huang, Wei,Zhao, Qiang
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p. 576 - 586
(2018/11/23)
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- Synthesis and characterization of novel heteroleptic Ru(II) bipyridine complexes for dye-sensitized solar cell applications
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Abstract: Four heteroleptic ruthenium(II) complexes, [Ru(L1)(L2)(NCS)2] (where L1 = 4,4′-bis[2-(1,1′-biphenyl)-4-ylethenyl]-2,2′-bipyridine (bpbpy) or 4,4′-bis[2-(3,4-dimethoxyphenyl)ethenyl]-2,2′-bipyridine (dmpbpy); L2 = 4,4′-dicarboxy-2,2′-bipyridine (dcbpy) or 4,4′-bis(E-carboxyvinyl)-2,2′-bipyridine (dcvbpy)), were synthesized from a one-pot reaction of [RuCl2(p-cymene)]2 and L1 followed by the addition of the anchoring ligand, L2. From these new heteroleptic ruthenium(II) complexes containing carboxylic acid-functionalized ligands, the tetrabutylammonium salt forms of the ruthenium(II) complexes, [Ru(L1)(L2)(NCS)2][TBA], were obtained in reasonable yields and applied as dyes in dye-sensitized solar cell (DSSC) devices. Among the DSSCs fabricated with the [Ru(L1)(L2)(NCS)2][TBA] dyes, a DSSC fabricated with the [Ru(bpbpy)(dcbpy)(NCS)2][TBA] dye exhibited the best power conversion efficiency (η) of 4.27%, while the cells fabricated with other dyes had η between 1.94 and 2.68%. Graphic abstract: [Figure not available: see fulltext.].
- Seo, Jinhyung,Jeong, Mingyeong,Na, Seo Yeong,Lee, Eugin,Kim, Yang-Rae,Park, Byoungchoo,Kim, Byeong Hyo
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p. 1445 - 1452
(2019/07/29)
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- Xylose derivatives and process for preparation thereof
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Disclosure of the present invention relates to a method for synthesis of a xylose derivative, which comprises protecting a xylose with a protective group, followed by incorporating to a halogen atom as a leaving group; removing the protective groups and using water-soluble ligands to carry out a Suzuki cross-couplings reaction with a palladium catalyst in a water solution. Ten new xylose derivatives as obtained by the method are also provided.
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- XYLOSE DERIVATIVES AND PROCESS FOR PREPARATION THEREOF
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Disclosure of the present invention relates to a method for synthesis of a xylose derivative, which comprises protecting a xylose with a protective group, followed by incorporating to a halogen atom as a leaving group removing the protective groups and using water-soluble ligands to carry out a Suzuki cross-couplings reaction with a palladium catalyst in a water solution. Ten new xylose derivatives as obtained by the method are also provided.
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- A water-soluble cyclometalated iridium(III) complex with fluorescent sensing capability for hypochlorite
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Herein, a novel cyclometalated iridium (III) complex (Ir-1) with good water-solubility was designed and synthesized to sensitively detect hypochlorite (ClO?) in aqueous buffer solution. The sensor Ir-1 was prepared by incorporating a methacrylate group into cyclometalated ligands, which was a specific response site toward ClO? through an oxidation process. Ir-1 displayed strong emission at 615 nm, while significant fluorescence quenching was observed upon addition of ClO? with a low detection limit of 0.41 μM. Moreover, probe Ir-1 exhibited a rapid response (? with high selectivity over potentially competing species. The sensing process was evidenced by NMR and MS characterization. Further application in bioimaging of ClO? was successfully performed in living HepG2 cells.
- Lu, Zhen,Shangguan, Mingqin,Jiang, Xingzong,Xu, Peiyao,Hou, Linxi,Wang, Tao
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- Anticancer IrIII–Aspirin Conjugates for Enhanced Metabolic Immuno-Modulation and Mitochondrial Lifetime Imaging
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The chemo-anti-inflammatory strategy is attracting ever more attention for the treatment of cancer. Here, two cyclometalated IrIII complexes Ir2 and Ir3 formed by conjugation of Ir1 with two antiphlogistics (aspirin and salicylic acid) have bee
- Wu, Xiao-Wen,Zheng, Yue,Wang, Fang-Xin,Cao, Jian-Jun,Zhang, Hang,Zhang, Dong-Yang,Tan, Cai-Ping,Ji, Liang-Nian,Mao, Zong-Wan
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supporting information
p. 7012 - 7022
(2019/05/07)
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- Synthesis and Characterization of Heteroleptic Ru(II) Complexes Based on 4,4′-Bis((E)-styryl)-2,2′-bipyridine as Ancillary Ligand and Application for Dye-Sensitized Solar Cells
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Heteroleptic Ru(II) complexes were designed based on 4,4′-bis((E)-styryl)-2,2′-bipyridine (bsbpy) as an ancillary ligand for dye-sensitized solar cells (DSSCs), and those Ru(II) sensitizers, [Ru(L)(bsbpy)(NCS)2][TBA] (TBA; tetrabutylammonium), were synthesized according to a typical one-pot reaction of [RuCl2(p-cymene)]2 with the corresponding anchoring ligands (where L?=?4,4′-dicarboxy-2,2′-bipyridine (dcbpy), 4,4′-bis((E)-carboxyvinyl)-2,2′-bipyridine (dcvbpy), 4,7-dicarboxy-1,10-phenanthroline (dcphen), or 4,7-bis((E)-carboxyvinyl)-1,10-phenanthroline (dcvphen)). The new Ru(II) dyes, [Ru(L)(bsbpy)(NCS)2][TBA] that incorporated vinyl spacer(s) into ancillary and/or anchoring ligand displayed red-shifted bands over the overall UV/VIS region relative to the absorption spectra of N719. A combination of bsbpy ancillary and dcphen anchoring ligand showed the best result for the overall power conversion efficiency (η); i.e., a DSSC fabricated with [Ru(dcphen)(bsbpy)(NCS)2][TBA] exhibited a power conversion efficiency (η) of 2.98% (compare to N719, 4.82%).
- Lee, Jihoon,Seo, Jinhyung,Choi, Yong Rack,Oh, Hyunju,Huh, Jun Nyeong,Park, Byoungchoo,Tak, Jungae,Kim, Byeong Hyo
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- Nanosecond transient absorption spectroscopy of a Ru polypyridine phenothiazine dyad
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A bipyridine phenothiazine ligand [(PTZEtv2bpy) and metal complexes [Ru(Ph2phen)3]2+(1), [(Ph2phen)2Ru(PTZEtv2bpy)]2+(2), and [(PTZEtv2bpy)(Ph2ph
- Kosgei, Gilbert K.,Livshits, Maksim Y.,Canterbury, Theodore R.,Rack, Jeffery J.,Brewer, Karen J.
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supporting information
p. 67 - 70
(2016/11/22)
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- Directly Coupled Versus Spectator Linkers on Diimine PtII Acetylides—Change the Structure, Keep the Function?
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Modification of light-harvesting units with anchoring groups for surface attachment often compromises light-harnessing properties. Herein, a series of [donor–acceptor–anchor] platinum(II) diimine (bis-)acetylides was developed in order to systematically compare the effect of conjugated versus electronically decoupled modes of attachment of protected anchoring groups on the photophysical properties of light-harvesting units. The first examples of “decoupled” phosphonate diimine PtII complexes are reported, and their properties are compared and contrasted to those of carboxylate analogues studied by a diversity of methods. Ultrafast time-resolved IR and transient absorption spectroscopy revealed that all complexes have a charge-transfer (CT) lowest excited state with lifetimes between 2 and 14 ns. Vibrational signatures and dynamics of CT states were identified; the assignment of electronic states and their vibrational origin was aided by TDDFT calculations. Ultrafast energy redistribution accompanied by structural changes was directly captured in the CT states. A significant difference between the structures of the electronic ground and CT excited states, as well as differences in the structural reorganisation in the complexes bearing directly attached or electronically decoupled anchoring groups, was discovered. This work demonstrates that decoupling of the anchoring group from the light-harvesting core by a saturated spacer is an easy approach to combine surface attachment with high reduction potential and ten times longer lifetime of the CT excited state of the light-absorbing unit, and retain electron-transfer photoreactivity essential for light-harvesting applications.
- Archer, Stuart A.,Keane, Theo,Delor, Milan,Bevon, Elizabeth,Auty, Alexander J.,Chekulaev, Dimitri,Sazanovich, Igor V.,Towrie, Michael,Meijer, Anthony J. H. M.,Weinstein, Julia A.
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p. 18239 - 18251
(2017/12/07)
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- A water-soluble and retrievable ruthenium-based probe for colorimetric recognition of Hg(II) and Cys
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A new ruthenium-based complex 1 [(bis(4,4′-dimethylphosphonic-2,2′-bipyridine) dithiocyanato ruthenium (II))] was developed as a colorimetric probe for the detection of Hg(II) and Cys (Cysteine). The obtained compound 1 can give interconversional color changes upon the alternating addition of Hg(II) and Cys in 100% aqueous solution. The specific coordination between NCS groups with Hg(II) can lead to the formation of 1-Hg2 + complex, which can induce a remarkable spectral changes of probe 1. Afterwards the formed 1-Hg2 + complex can act as effective colorimetric sensor for Cys. Owing to the stronger binding affinity of sulfhydryl group to Hg2 +, Cys can extract Hg2 + from 1-Hg2 + complex resulting in the release of 1 and the revival of absorption profile of the probe 1. By introducing the hydrophilic phosphonic acid groups, the proposed probe exhibited excellent water solubility. The limits of detection (LODs) of the assay for Hg2 + and Cys are calculated to be 15 nM and 200 nM, respectively.
- Cui, Yali,Hao, Yuanqiang,Zhang, Yintang,Liu, Baoxia,Zhu, Xu,Qu, Peng,Li, Deliang,Xu, Maotian
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p. 150 - 154
(2016/05/09)
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- Copper oxide surfaces modified by alkylphosphonic acids with terminal pyridyl-based ligands as a platform for supported catalysis
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Self-assembled monolayer (SAM) films of phosphonates have been successfully formed via reaction of 11-hydroxyundecylphosphonic acid or 4,4′-di(methylenephosphonic acid)-2,2′-bipyridine with the oxide layer of copper via the Tethering by Aggregation and Growth (TBAG) deposition method. The hydroxyl-terminated SAM was further modified with isonicotinic acid or 4,4′-dicarboxy-2,2′-bipyridine through a Steglich esterification reaction. These three surfaces derivatized with pyridyl-based ligands are potential platforms for supported catalysis. As a proof of concept, [Ru(CO)3Cl2]2 was bound to the surfaces through the pyridyl-based ligands to yield tethered analogs of the known carbon dioxide reduction catalyst, [Ru(bpy)(CO)2Cl2]. Surface modification reactions were confirmed through specular reflectance infrared (IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Characteristic core binding energies were observed in the XPS analyses for phosphorus (P 2p), nitrogen (N 1s), and ruthenium (Ru 3p and Ru 3d), verifying the presence of the various surface functionalizations. IR and XPS data indicate that the phosphonate binding to the copper surface is tridentate in nature.
- Andrews, Brooke,Almahdali, Sarah,James, Karmel,Ly, Sandrine,Crowder, Katherine N.
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p. 360 - 369
(2016/07/06)
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- The phosphorescence a ionic complex and its preparation method and application (by machine translation)
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This invention relates to a kind of ionic phosphorescent iridium complex and its preparation method and application, and in particular relates to a L-ascorbic acid for detecting the phosphorescence of the complex. This kind of complex material by the ring metal-ligand, metal center and nitroxyl radical modified auxiliary ligand, the general structure is as the following formula. As the iridium complex has low biological toxicity, is easy to enter into cytolymph emission of phosphorescence in long service life and, therefore, the the ascorbic acid detection, time-resolved techniques and cell imaging, there is a broad application prospect. (by machine translation)
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- Metal-based tris-bipyridyl complexes and uses thereof in electrochromic applications
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The present invention relates to metal-based tris-bipyridyl complexes, e.g., iron-based tris-bipyridyl complexes, and their use in fabrication of surface confined assemblies for electrochromic applications.
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- Post-synthetic modifications of cadmium-based knots and links
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Three topologically non-trivial cadmium(ii)-based complexes - Cd-[2]C, Cd-TK and Cd-SL - were simultaneously self-assembled in a dynamic library, individually isolated and fully characterized using solid-state, gas-phase and solution-phase techniques. Post-synthetic modifications, including reduction and transmetalation, were subsequently achieved. Imine bond reduction followed by demetallation led to the isolation of the corresponding organic molecules [2]C, TK and SL. Transmetalation of Cd-TK and Cd-SL with the zinc(ii) cation resulted in isolation of the corresponding zinc(ii)-containing complexes Zn-TK and Zn-SL.
- Prakasam, Thirumurugan,Bilbeisi, Rana A.,Lusi, Matteo,Olsen, John-Carl,Platas-Iglesias, Carlos,Trabolsi, Ali
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p. 7398 - 7401
(2016/06/14)
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- Pyridinium-based ionic phosphorescent iridium complex probe and preparation method and biotechnological application thereof
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The invention relates to a pyridinium-based ionic phosphorescent iridium complex probe and a preparation method and biotechnological application thereof, in particular to phosphorescent iridium complex for detecting and reducing glutathione, cysteine, hydrogen sulfide and other sulfydryl containing reductive substances and application of the phosphorescent iridium complex in detecting the redox state in cells, and belongs to the technical field of organic photoelectric functional materials. The complex material is prepared from cyclometalated ligand, a metal center (iridium) and pyridinium group modified auxiliary ligand, and the structure of the complex is shown as the following formula. The complex has wide application prospects on the technical aspects of detecting the redox state in the cells, phosphorescence lifetime imaging and time resolution. The formula can be seen in the specification.
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- Electronically Neutral Metal Complexes As Biological Labels
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The invention relates to electronically neutral metal complexes as luminescent labels. The positive charge of the metal ion in the complex is neutralized by the negatively charged groups that are covalently linked to the nitrogen-containing diimine ligands, such as 2,2-bipyridine, 1,10-phenanthroline and their derivatives. The electronic neutrality reduces the impact of the metal complexes on the biological and/or biochemical activities of the labeled biomolecules, while the intensity of luminescent emission under electrochemical excitation is enhanced. These luminescent metal complex labels are useful in bioanalytic methodology development, with luminescence as the signal modality, such as electrochemiluminescence.
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- LUMINESCENT RUTHENIUM (II) COMPLEXES AND THEIR USE IN PH SENSORS
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The invention provides luminescent Ru(ll) complexes that can be used in pH sensors to provide pH sensitivity over a wide pH range. The complexes have at least one polypyridyl ligand having at least one proton-accepting group with a pKa in the range 4 to less than 6, wherein the luminescence intensity and/or luminescence lifetime of the complex varies depending on the protonation state of the proton-accepting group; and at least one polypyridyl ligand having at least one proton-donating group with a pKa in the range 6 to 8, wherein the at least one proton-donating group is covalently linked to a ring carbon atom of the at least one polypyridyl ligand by a spacer group having the formula -(CH2)q- wherein q may be 1, 2, or 3, and wherein the luminescence intensity and/or luminescence lifetime of the complex varies depending on the protonation state of the proton-donating group.
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Page/Page column 26
(2016/06/01)
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- Dynamic stereoisomerization in inherently chiral bimetallic [2]catenanes
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Stereoisomerization and the unprecedented phenomenon of metal translocation in the absence of redox processes were probed in two inherently chiral bimetallic [2]catenanes by using a combination of variableerature 1H NMR and CD spectroscopies, X-ray crystallography, and DFT calculations.
- Prakasam, Thirumurugan,Lusi, Matteo,Nauha, Elisa,Olsen, John-Carl,Sy, Mohamadou,Platas-Iglesias, Carlos,Charbonnière, Lo?c J.,Trabolsi, Ali
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p. 5840 - 5843
(2015/03/31)
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- Synthesis and characterization of an immobilizable photochemical molecular device for H2-generation
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With [RuII(bpyMeP)2tpphzPtCl2]2+ (4) a molecular photocatalyst has been synthesized for visible-light-driven H2-evolution. It contains the ligand bpyMeP (4,4′-bis(diethyl-(methylene)-phosphonate)-2,2′-bipyridine) with phosphate ester groups as precursors for the highly potent phosphonate anchoring groups, which can be utilized for immobilization of the catalyst on metal-oxide semiconductor surfaces. The synthesis was optimized with regard to high yields, bpyMeP was fully characterized and a solid-state structure could be obtained. Photophysical studies showed that the photophysical properties and the localization of the excited states are not altered compared to similar Ru-complexes without anchoring group precursors. (4) was even more active in homogenous catalysis experiments than [RuII(tbbpy)2tpphzPtCl2]2+ (6) with tbbpy (4,4′-bis(tbutyl)-2,2′-bipyridine) as peripheral ligands. After hydrolysis (4) was successfully immobilized on NiO, suggesting that an application in photoelectrosynthesis cells is feasible. This journal is
- Braumüller, Markus,Schulz, Martin,Sorsche, Dieter,Pfeffer, Michael,Schaub, Markus,Popp, Jürgen,Park, Byung-Wook,Hagfeldt, Anders,Dietzek, Benjamin,Rau, Sven
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p. 5577 - 5586
(2015/03/30)
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- Iodide ion pairing with highly charged ruthenium polypyridyl cations in CH3CN
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A series of three highly charged cationic ruthenium(II) polypyridyl complexes of the general formula [Ru(deeb)3-x(tmam)x](PF6)2x+2, where deeb is 4,4′-diethyl ester-2,2′-bipyridine and tmam is 4,4′-bis[(trimethylamino)methyl]-2,2′-bipyridine, were synthesized and characterized and are referred to as 1, 2, or 3 based on the number of tmam ligands. Crystals suitable for X-ray crystallography were obtained for the homoleptic complex 3, which was found to possess D3 symmetry over the entire ruthenium complex. The complexes displayed visible absorption spectra typical of metal-to-ligand charge-transfer (MLCT) transitions. In acetonitrile, quasi-reversible waves were assigned to RuIII/II electron transfer, with formal reduction potentials that shifted negative as the number of tmam ligands was increased. Room temperature photoluminescence was observed in acetonitrile with quantum yields of φ ~ 0.1 and lifetimes of τ ~ 2 μs. The spectroscopic and electrochemical data were most consistent with excited-state localization on the deeb ligand for 1 and 2 and on the tmam ligand for 3. The addition of tetrabutylammonium iodide to the complexes dissolved in a CH3CN solution led to changes in the UV-vis absorption spectra consistent with ion pairing. A Benesi-Hildebrand-type analysis of these data revealed equilibrium constants that increased with the cationic charge 1 -1. 1H NMR studies in CD3CN also revealed evidence for iodide ion pairs and indicated that they occur predominantly with iodide localization near the tmam ligand(s). The diastereotopic H atoms on the methylene carbon that link the amine to the bipyridine ring were uniquely sensitive to the presence of iodide; analysis revealed that an iodide "binding pocket" exists wherein iodide forms an adduct with the 3 and 3′ bipyridyl H atoms and the quaternized amine. The MLCT excited states were efficiently quenched by iodide. Time-resolved photoluminescence measurements of 1 revealed a static component consistent with rapid electron transfer from iodide in the "binding pocket" to the Ru metal center in the excited state, ket > 108 s-1. The possible relevance of this work to solar energy conversion and dye-sensitized solar cells is discussed.
- Swords, Wesley B.,Li, Guocan,Meyer, Gerald J.
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p. 4512 - 4519
(2015/05/20)
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- New iridium complexes with two pre-organized urea groups and thiourea groups as phosphorescent chemosensors for H2PO4 - and chiral carboxylates
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As a versatile platform for phosphorescent chemosensors, bis(benzylic amine) derivative 6 was synthesized. Two urea groups could be readily introduced for phosphorescent chemosensor 1. A preorganized binding pocket could induce a selective phosphorescence
- Li, Yinan,Liu, Yifan,Nam, Dayoung,Park, Sungnam,Yoon, Juyoung,Hyun, Myung Ho
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p. 241 - 246
(2013/10/22)
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- New bi-functional zinc catalysts based on robust and easy-to-handle N-chelating ligands for the synthesis of cyclic carbonates from epoxides and CO2 under mild conditions
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A series of novel zinc complexes were prepared by covalent linkage of various imidazolium-based ionic liquid moieties with the 2,2′-bipyridine ligand on the two sides of the 4,4′-position. The zinc(ii) complexes containing the rigid N-chelating ligand proved to be stable, highly efficient and easy-to-handle catalysts towards the synthesis of cyclic carbonate from epoxide and CO2 without the use of any co-catalyst or organic solvent. The catalysts can be easily recovered and reused without significant loss of activity and selectivity by control of the solvent. The kinetic study uncovered that the reaction was first-order with respect to the epoxide. Moreover, a plausible reaction mechanism was proposed, in which the zinc center could promote ring-opening of the epoxide for the synergetic effect with the anion X- in ILs. the Partner Organisations 2014.
- Luo, Rongchang,Zhou, Xiantai,Zhang, Wuying,Liang, Zhongxiu,Jiang, Jun,Ji, Hongbing
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p. 4179 - 4189
(2014/09/30)
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- Study of asymmetric aldol and Mannich reactions catalyzed by proline-thiourea host-guest complexes in nonpolar solvents
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A proline-thiourea host-guest complex has been described as a good catalyst for asymmetric reactions such as aldol and Mannich reactions. High stereoselectivities were obtained under optimal conditions. Thiourea was observed to have an important effect on the reactivity and selectivity, even in an unconventional nonpolar reaction medium and without the need to utilize low temperatures. This proline-thiourea host-guest system has the ability to participate in a hydrogen bonding network.
- Demir, Ayhan Sitki,Basceken, Sinan
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p. 515 - 525
(2013/06/26)
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- Simultaneous self-assembly of a [2]catenane, a trefoil knot, and a solomon link from a simple pair of ligands
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A topological triptych: Three molecular links, a [2]catenane, a trefoil knot, and a Solomon link, were obtained in one pot through the self-assembly of two simple ligands in the presence of ZnII (see picture). The approach relied on dynamic covalent chemistry and metal templation.
- Prakasam, Thirumurugan,Lusi, Matteo,Elhabiri, Mourad,Platas-Iglesias, Carlos,Olsen, John-Carl,Asfari, Zouhair,Cianferani-Sanglier, Sarah,Debaene, Francois,Charbonniere, Loic J.,Trabolsi, Ali
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p. 9956 - 9960
(2013/10/01)
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- Synthesis of phosphonic acid derivatized bipyridine ligands and their ruthenium complexes
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Water-stable, surface-bound chromophores, catalysts, and assemblies are an essential element in dye-sensitized photoelectrosynthesis cells for the generation of solar fuels by water splitting and CO2 reduction to CO, other oxygenates, or hydrocarbons. Phosphonic acid derivatives provide a basis for stable chemical binding on metal oxide surfaces. We report here the efficient synthesis of 4,4′-bis(diethylphosphonomethyl)-2,2′- bipyridine and 4,4′-bis(diethylphosphonate)-2,2′-bipyridine, as well as the mono-, bis-, and tris-substituted ruthenium complexes, [Ru(bpy) 2(Pbpy)]2+, [Ru(bpy)(Pbpy)2]2+, [Ru(Pbpy)3]2+, [Ru(bpy)2(CPbpy)]2+, [Ru(bpy)(CPbpy)2]2+, and [Ru(CPbpy)3] 2+ [bpy = 2,2′-bipyridine; Pbpy = 4,4′-bis(phosphonic acid)-2,2′-bipyridine; CPbpy = 4,4′-bis(methylphosphonic acid)-2,2′-bipyridine].
- Norris, Michael R.,Concepcion, Javier J.,Glasson, Christopher R. K.,Fang, Zhen,Lapides, Alexander M.,Ashford, Dennis L.,Templeton, Joseph L.,Meyer, Thomas J.
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p. 12492 - 12501
(2013/11/19)
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- Ln2M complexes (M = Ru, Re) derived from a bismacrocyclic ligand containing a 4,4′-dimethyl-2,2′-bipyridyl bridging unit
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Homodinuclear lanthanide complexes derived from a ligand featuring two DO3A chelating sites linked by a 4,4′-dimethyl-2,2′-bipyridyl spacer were prepared and characterized. The bipyridyl coordination site of 1 was used to introduce Ru(Bpy)2 and Re(CO)3Cl moieties, leading to the formation of heterometallic d-f2 complexes with general formulae [Ln2·1·Ru(Bpy)2]2+ (Ln = Nd, Eu, Tb, Yb and Lu) and [Ln2·1·Re(CO)3Cl] (Ln = Nd, Yb and Lu). The luminescence properties of the complexes were investigated by means of absorption spectroscopy and steady-state and time-resolved luminescence spectroscopy covering the visible and NIR regions. Both Ru and Re chromophores were shown to act as efficient sensitizers of the NIR emission of Yb and Nd in aqueous solutions. We also consider the unsaturated coordination spheres of the Ln cations in the Ln2·1 complexes, which form ternary complexes with bidentate anions without showing particular synergistic effects for polyanionic species.
- Charbonniere, Loic J.,Faulkner, Stephen,Platas-Iglesias, Carlos,Regueiro-Figueroa, Martin,Nonat, Aline,Rodriguez-Blas, Teresa,De Blas, Andres,Perry, William S.,Tropiano, Manuel
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p. 3667 - 3681
(2013/03/28)
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- Polymer-based fluorescent sensor incorporating 2,2′-bipyridyl and benzo[2,1,3]thiadiazole moieties for Cu2+ detection
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The polymer was synthesized by the polymerization of 4,4′-((4- iodophenoxy)methyl)-2,2′-bipyridine (M-1) with 4,7-diethynylbenzo[2,1,3]- thiadiazole (M-2) via Pd-catalyzed Sonogashira reaction. The fluorescence responses of the polymer towards various tra
- Dong, Yu,Koken, Biyhaliy,Ma, Xiao,Wang, Lu,Cheng, Yixiang,Zhu, Chengjian
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scheme or table
p. 1719 - 1722
(2011/11/30)
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- High spectral response heteroleptic ruthenium (II) complexes as sensitizers for dye sensitized solar cells
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Heteroleptic ruthenium(II) bipyridyl complex, cis-Ru(II)(4,4'-bis(4-tert- butylstyryl)-2,2'-bipyridyl) (4,4'-dicarboxy-2,2'-bipyridyl) (NCS2) (H112) was synthesized and characterized by 1H-NMR, MASS, Spectrofluorometer and UV-Vis spectroscopes. The photo-voltaic performance of the sensitizer was evaluated in Dye Sensitized Solar Cell (DSSC) under irradiation of AM 1.5 G solar light and the photovoltaic characteristics were compared with those of reference cells of HRS1 and N719 fabricated under comparable conditions. Compared to N719, H112 sensitizer showed enhanced molar extinction coefficient and relatively better monochromatic incident photon-to-current conversion efficiency (IPCE) across the spectral range of 400 to 800 nm with solar energy-to-electrical conversion efficiency (η) of 2.43% [open circuit photovoltage (VOC) = 0.631V, short-circuit photocurrent density (JSC) = 8.96 mA/cm2, fill factor (ff) = 0.430], while η values of 2.51% (VOC = 0.651 V, JSC = 9.41mA/cm 2, ff = 0.410) and 2.74% (VOC = 0.705 V, JSC = 8.62 mA/cm2, ff = 0.455) were obtained for HRS1 and N719 sensitized solar cells respectively. The introduction of 4,4'-bis(4-tert-butylstyryl) moieties on one of the bipyridine moieties of N719 complex shows higher light absorption abilities, IPCE and JSC. Indian Academy of Sciences.
- Chandrasekharam,Srinivasarao,Suresh,Reddy, M. Anil,Raghavender,Rajkumar,Srinivasu,Reddy, P. Yella
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- Synthesis and characterization of cross-linkable ruthenium dye with ion coordinating property for dye-sensitized solar cells
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Crosslinkable ruthenium complex dye, Ru(2,2′-bipyridine-4,4′- bicarboxylic acid)(4,4′-bis((4-vinyl benzyloxy)methyl)-2,2′- bipyridine)(NCS)2 (denoted as Ru-S dye), was synthesized and characterized using 1H-NMR, 13C-NMR, Fourier transform infrared (FTIR) and UV/vis spectroscopies.The power conversion efficiency of dye-sentitized solar cell (DSSC) using Ru-S and liquid electrolyte containing lithium iodide (LiI) reached 7.53% under standard global AM 1.5 full sunlight, which is partly attributed to Li+ being coordinated by Ru-S as verified by ATR-FTIR spectroscopy. As Ru-S was further crosslinked with glycerol propoxylate triacrylate (GPTA), not only 89% of dye retained on TiO2 mesoporous surface after rinsed by 0.1 N NaOH aqueous solution, the power efficiency was also increased to 7.88%. As poly(methyl acrylate) was used to gel the electrolyte system, the power efficiency of DSSC with Ru-S dye was 6.96% but increased to 7.57% after crosslinking with GPTA. Notably, both DSSCs showed a good long-term stability after one month storage.
- Liu, Ken-Yen,Ko, Chih-Yang,Ho, Kuo-Chuan,Lin, King-Fu
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p. 3318 - 3324
(2012/05/31)
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- Synthesis and properties of novel low band-gap polymers bearing squaraine units
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Novel main-chain-conjugated poly(carbazol-alt-squaraine) and poly(dipyridyl-alt-squaraine) were successfully synthesized through direct polycondensation of 9-(2-ethylhexyl)carbazole-bridged or dipyridyl-bridged bispyrrole and squaric acid. The structures
- Zhang, Wei,Wang, Zheng,Tang, Yu Sheng,Xu, Zhi Gang,Li, Ying,Jiang, Qing
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experimental part
p. 245 - 248
(2010/12/24)
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- Convenient synthesis of functionalized 4,4′-disubstituted-2,2′- bipyridine with extended π-system for dye-sensitized solar cell applications
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Exploration of new ruthenium-based sensitizers for dye-sensitized solar cell (DSC) applications requires an easy access to multifunctionalized ligands for efficient screening of sensitizers' properties. Based on the Horner-Emmons-Wadsworth reaction, a convenient synthetic route for the extension of the π-system on 4,4′-disubstituted-2,2′-bipyridines was used to develop a novel series of functionalized 2,2′-bipyridine ligands with either electron-withdrawing or donating end-capping group. 1H NMR spectroscopy revealed that all the new bipyridyl ligands were obtained exclusively in their fully E isomers.
- Klein, Cédric,Baranoff, Etienne,Nazeeruddin, Md. Khaja,Gr?tzel, Michael
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scheme or table
p. 6161 - 6165
(2011/01/04)
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- Enhanced electrochemiluminescence efficiency of Ru(ii) derivative covalently linked carbon nanotubes hybrid
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The synthesized derivative Ru(bpy)3 covalently linked CNTs hybrid shows good electrochemical activity and ca. 17 times higher luminescence quantum efficiency than the adsorbed derivative Ru(bpy)3. The Ru-CNTs based ECL sensor exhibits high stability toward determination of TPA with a detection limit as low as 8.75 pM.
- Li, Jing,Guo, Li-Rong,Gao, Wei,Xia, Xing-Hua,Zheng, Li-Min
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supporting information; experimental part
p. 7545 - 7547
(2010/04/28)
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- NOBLE RUTHENIUM-TYPE SENSITIZERS AND METHOD OF PREPARING THE SAME
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The present invention relates to a noble ruthenium-type dye and a making method thereof, and more particularly, to a noble ruthenium- type dye(sensitizer) which is used to manufacture a dye-sensitized solar cell, drastically improves a photoelectric conve
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Page/Page column 26; 29
(2008/12/08)
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- Artificial G-wire switch with 2,2′-bipyridine units responsive to divalent metal ions
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Development of a guanine nanowire (G-wire) that is controllable and can be switched by external signals is important for the creation of molecular electronic technologies. Here, we constructed a G-wire in which the thymines of the main chain of d(G4T4G4) were replaced with 2,2′-bipyridine units, which have two aromatic rings that rotate arbitrarily upon coordination with metal ions. Circular dichroism of the DNA oligonucleotides with or without the 2,2′-bipyridine unit showed that divalent metal ions induce the bipyridine-containing oligonucleotide to switch from an antiparallel to a parallel G-quadruplex. Native polyacrylamide gel electrophoresis showed that the parallel-stranded G-quadruplex DNA had a high-order structure. Circular dichroism and native gel electrophoresis analyses suggested that adding Na2EDTA causes a reverse structural transition from a parallel-stranded high-order structure to an antiparallel G-quadruplex. Moreover, atomic force microscopy showed a long nanowire (~200 nm) in the presence of Ni2+ but no significant image in the absence of Ni 2+ or in the presence of both Ni2+ and Na2EDTA. These observations revealed that the parallel-stranded high-order structure is a G-wire containing numerous DNA oligonucleotide strands bound together via divalent metal ion-2,2′-bipyridine complexes. Finally, we found that alternating addition of Ni2+ and Na2EDTA can cycle the G-wire between the high-order and disorganized structures, with an average cycling efficiency of 0.95 (i.e., 5% loss per cycle). These results demonstrate that a DNA oligonucleotide incorporating the 2,2′-bipyridine unit acts as a G-wire switch that can be controlled by chemical input signals, namely, divalent metal ions.
- Miyoshi, Daisuke,Karimata, Hisae,Wang, Zhong-Ming,Koumoto, Kazuya,Sugimoto, Naoki
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p. 5919 - 5925
(2008/02/06)
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- Synthesis, Characterization and Photochromic Studies of Spirooxazine-Containing 2,2′-Bipyridine Ligands and Their Rhenium(I) Tricarbonyl Complexes
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A series of spirooxazine-containing 2,2′-bipyridine ligands and their rhenium(I) tricarbonyl complexes has been designed and synthesized, and their photophysical, photochromic and electrochemical properties have been studied. The X-ray crystal structures
- Ko, Chi-Chiu,Wu, Li-Xin,Wong, Keith Man-Chung,Zhu, Nianyong,Yam, Vivian Wing-Wah
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p. 766 - 776
(2007/10/03)
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- Synthesis of C2 symmetric 2,2′-bipyridyl imidazolidinone and oxazaborolidine derivatives
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4,4′-Bis(bromomethyl)-2,2′-bipyridine reacts with (4R, 5R)-1-propanoyl-4,5-diphenylimidazolidinone to form a C2 symmetric chiral bipyridine derivative. Similarly reaction of 4,4′-bis(bromomethyl)-2,2′-bipyridine with an amino alcohol prepared from L-tyrosine affords a C2 symmetric diaminodiol. Treatment of the latter product with either borane or trimethylboroxine forms oxazaborolidines that have been used as catalysts in the asymmetric reduction of acetophenone. High enantiomeric excesses are obtained.
- Ward, Robert S.,Branciard, Denis,Dignan, Rosemary A.,Pritchard, Martyn C.
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p. 157 - 170
(2007/10/03)
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- Covalently linked ruthenium(II)-manganese(II) complexes: Distance dependence of quenching and electron transfer
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Continuing our development of artificial models for photosystem II in green plants, a series of compounds have been prepared in which a Ru(bpy)32+ photosensitizer is covalently linked to a manganese(II) electron donor. In addition to a trispicolylamine ligand, two other manganese ligands, dipicolylamine and aminodiacetic acid, have been introduced in order to study ligands that are appropriate for the construction of manganese dimers with open coordination sites for the binding of water. Coordination equilibria of the manganese ions were monitored by EPR. The interactions between the ruthenium and manganese moieties were probed by flash photolysis, cyclic voltammetry and steady-state and time-resolved emission measurements. The quenching of the RuII excited state by MnII was found to be rapid in complexes with short Ru-Mn distances. Nevertheless, each RuII species could be photo-oxidized by bimolecular quenching with methylviologen, and the subsequent electron transfer from MnII to RuIII could be monitored.
- Berg, Katja E.,Tran, Anh,Raymond, Mary Katherine,Abrahamsson, Malin,Wolny, Juliusz,Redon, Sophie,Andersson, Mikael,Sun, Licheng,Styring, Stenbj?rn,Hammarstr?m, Leif,Toftlund, Hans,?kermark, Bj?rn
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p. 1019 - 1029
(2007/10/03)
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- An improved synthesis of hydroxymethyl bipyridines
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This account describes quick and efficient syntheses of 4,4'- bis(hydroxymethyl)-2,2'-bipyridine and 4-hydroxymethyl-2,2'-bipyridine from 4,4'-dimethyl-2,2'-bipyridine and 4-methyl-2,2'-bipyridine, respectively, via (trimethylsilyl)methyl-, bromomethyl-, and acetoxymethyl- intermediates. (C) 2000 Elsevier Science Ltd.
- Smith, Adam P.,Corbin, Perry S.,Fraser, Cassandra L.
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p. 2787 - 2789
(2007/10/03)
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- Potentiostatic modulation of the lifetime of light-induced charge separation in a heterosupermolecule
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A heterosupermolecule has been assembled by covalently linking a TiO2 nanocrystal, a ruthenium complex, and a viologen. The associated heterosupramolecular function, long-lived light-induced charge separation, has been demonstrated. Potentiostatic modulation of this function has also been demonstrated. The reported findings and associated insights may find practical applications in the area of optical information storage. ? 1999 American Chemical Society.
- Will, Geoffrey,Boschloo, Gerrit,Rao, S. Nagaraja,Fitzmaurice, Donald
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p. 8067 - 8079
(2007/10/03)
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- Cyclophanes and [2]catenanes as ligands for transition metal complexes: Synthesis, structure, absorption spectra, and excited state and electrochemical properties
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Two novel cyclophanes (L14+ and Ln24+), derived from the previously investigated cyclobis(paraquat-p-phenylene) tetracation by the replacement of one and two p-phenylene spacers by 2,2'-bipyridine units suitable
- Ashton, Peter R.,Balzani, Vincenzo,Credi, Alberto,Kocian, Oldrich,Pasini, Dario,Prodi, Luca,Spencer, Neil,Stoddart, J. Fraser,Tolley, Malcolm S.,Venturi, Margherita,White, Andrew J. P.,Williams, David J.
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p. 590 - 607
(2007/10/03)
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- Design, synthesis and structural analysis of exoditopic macrocyclic ligands based on bipyridine units
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The synthesis of new unsymmetrical and symmetrical macrocycles based on 2,2'-bipyridine units bearing two or four phenyl groups at the 6 and 6' positions was achieved by an oxidative coupling reaction using 1,2-dibromoethane and organolithium derivatives of bipyridine. Among all new compounds prepared, two of them were structurally analysed in the solid state by X-ray diffraction.
- Kaes, Christian,Hosseini, Mir Wais,De Cian, Andre,Fischer, Jean
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p. 4389 - 4392
(2007/10/03)
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- Synthesis of Halomethyl and Other Bipyridine Derivatives by Reaction of 4,4′-Bis[(trimethylsilyl)methyl]-2,2′-bipyridine with Electrophiles in the Presence of Fluoride Ion
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Bipyridine (bpy) ligands figure prominently in many areas of chemistry. Common precursors to many derivatives are the halomethyl-substituted analogues. This report describes a new, high yield route to these valuable compounds via a trimethylsilyl (TMS) in
- Fraser, Cassandra L.,Anastasi, Natia R.,Lamba, Jaydeep J. S.
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p. 9314 - 9317
(2007/10/03)
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